Piston ring spacer and expander



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A ril 23, 1957 H. M. OLSON PISTON RING SPACER AND EXPANDER Filed March 7. 1955 INVENTORM H'0//y M, Q/g WET Afforne g internal combustion engine.

United States M Patent PISTON RING SPACER AND EXPANDER Holly M. Olson, Muskegon, Mich., assignor to Sealed Power Corporation, Muskegon, Mich., a corporation of Michigan Application March 7, 1955, Serial No. 492,564

2 Claims. (Cl. 309-45)" The present invention relates to a novel, one-piece, circumferentially, resistingly compressible spacer and expander adapted to be located between upper and lower thin metallic rails in the oil groove of a piston in an The construction devised which embodies my invention is expeditiously and economically made from flat ribbon stock having considerable resistance to strain but which in my invention, at generally equally spaced intervals, has portions which are reduced in cross-sectional area and formed so that the strain and deformation which is required to circumferentially compress the spacer-expander is reduced and controlled within desired limits.

The invention is an improvement upon and in connection with my Patent No. 2,637,607, granted May 5, 1953, the structure of which is altered and modified by providing oil venting slotsat spaced intervals. The slots are centrally located between the rails which are associated with the spacer expander and provide ample oil passage direct to the bottom of the piston ring groove in which installed, with a return of excess oil to the crankcase of the engine. Such slots are also located soas to provide a controlled flexing tension when the spacer expander is compressed and the rails associated therewith closed at their partings. The inner edges of the rails are pressed against by upwardly and downwardly extending lips or pads of a height slightly less than the thickness of the rails, the rails being pressed against at spaced intervals, and all flexing of the spacer expander when circumferentially compressed occurs at such slotted portions of the expander. Such pads or lips at the sides where they bear against the inner edges of the rails may be inwardly inclined at an angle to the plane of the portions of the spacer expander with which integrally connected, whereby the rails are brought into a better and closer sealing engagement with the sides of the piston ring groove in which the installation of the spacer expander with its associated rails is made. Such desirable functions arise from such compressible character of the spacer expander which, made in one piece, there is no necessity for a bottom rest against which the expander engages. Equal. and uniform performance is attained irrespective of the usual variations of the piston ring groove depth or itsbottom construction, Whether substantially closedor large-- ly open.

An understanding of the invention may be had from the following description, taken in connection with the accompanying drawing, in which,

Fig. l is a fragmentary plan view of a portion of a length of the ribbon stock fro-m which the spacer ex-- pander is made after the first step of manufacture has been completed for forming and shaping the material with outwardly extending pads or lips and spaced venting slots.

Fig. 2 is a plan view of the spacer expander of my invention having associated therewith the thin rails which 2,789,872 Patented Apr. 23,

ice

2 are used to complete a piston ring with such' spacer expander closed at its parting at one side thereof.

- Fig.3 is a fragmentary perspective view, somewhat-enlarged, of a section of the spacer expander made inaccordance with my invention, and s r 1 Fig. 4 is afragmentary enlarged vertical section through a piston and associatedcylinder in which installed atthe lower oil groove of such piston, with a piston ring including rails and the spacer expander of my invention installed in such groove.

Like reference characters refer to like parts in the different figures of the drawing. i a

The spacer expander of my invention comprises a member generally circular in outline, parted at one side and consisting in the main of -a consecutive series of alternate inward and outward corrugations. The inner corrugations have crowns 1 and the outer crowns 2'w hich are connected by upper and lower connecting legs '3 separated by slots 4. Such slots 4 paralleling the upper and lower edges of the spacer expander extend from the edges of the crowns 1 to and partly into the crowns 2 as shown in Fig. 3. From each of the inner crowns 1 a short lip or pad 5 extends at both upper and lower edges. I Such pads extend upwardly above and downwardly below the edges of the spacer expander respectively and are of narrow width. Theends of the spacer expander member are turned outwardly in'terminal lips 6. (Fig. 2) which at adjacent sides abut against each other. It is apparent, as fully shown in Fig. 3, that each connecting .leg 3 and each part thereof above and below the slot 4 therein has reversely curved end portions extending from a middle portion and that slots 4 reach-from one curved end portion to the other, providing a readily controlled, uniform flexibility in the several connecting legs in circumferentially contracting the spacer and expander. I I j Such structure is made from a single length of flat metal material. The connecting portions between the inner and outer crowns, because of their location and because of the removal of the metal when the slots 4 are made, have flexibility so that they yield when the spacer expander member is contracted circumferentially, the abutting end portions 6 pressing against each other. It is evident that such spacer expander member is readily made from flat ribbon stock of a desired thickness, the openings provided by theslots at 4 being easily made by punching metal from the strip stock, the lips or pads 5 being left upon cutting metal between successive lips or pads at the side edges of the stock.

With such spacer expander, thin parted metal rails 7 are used, one at the upper and one at the lower side, the inner edges of which come against the outer sides of the lips or pads 5. The corrugations extending outwardly from the crowns 1 lie between the upper and lower sides of the lower and upper rails respectively, providing support therefor and holding them spaced. The rails at their outer edges extend beyond the spacer expander a short distance but such outwardly extending corrugations provide ample and stable support for the rails. In practice it may be desirable to incline the lips or pads 5 at an angle, which may be between 5 to 25, to the planes of the inner crowns 1 as shown in Fig. 4, so that the inner edges of the rails 7 pressing thereagainst will cause the inner portions of said rails to tend to move into a sealing engagement against the opposite sides of a ring groove in a piston in which the piston ring, consisting of the rails and novel spacer expander of my invention, is installed.

'The width of the lips 5, that is, the distance they extend .locationiwithina .cylinder..9 .is .shown. .The lower roil groove in the piston has a drainage outlet 11 from the bottom of such groove to the interior of the piston. -The.,piston..ring installed in such groove, consisting .of.the rails 7 an'dihenov'el.spacerexpander .of my.invention,ha s the .rails. at :.their. .outer' sides .against opposed. sides of the ring .groove '10 .and :their outer edges .bearing with pressure against the cylinderwalls. ;.The innerfedgesof .the .railsfl are.in.tightengagement,withthe outer edges of ..the.lips;5. The spacerexpanderis circumferentially cornpressed,causes,forcesitherein..which,hecause of the resist- ;ance of thdspaceiexpandermembersto such compression, generates radial forces imparted by the lips .orpads' 5.to the,rails1t7iatitheirlinneriedgessto causethemto hear at their outer edges with a desirednnit pressureagainst the v.cylinderrwalls.

hepspacer. expander;.of mysinvention is sturdy and ..may1be, made .of..relatively heavytribbon stockwith the acquired.fiexibilitycomingiromdecreasing the cross sec- .tiQnaLarca ,of such stockibyrcuttingitheuslots .4 therein whichtslots being located. in the legsof the corrugations .Mhichconnect .the inner and .outer crowns,,pr ovide not only ampleventingfortheflow oflubricating oil through thespacer expandertothe bottornofthe ring. groove, but .lessrsndhe resistance .to-bending orzflexing whichwould .bepresent; if suchslotswere not used .or made at the crown ,portionsof the spacer expander.

Suchspacer expander retains its .necessary properties ;.f or,etI ectiVe operation inan increasing degree because of ,Jheatrongand sturdy nature of the metallic ribbon ma- ,terial' from whichrnade. Thelifeof use ofsuch expander ,js therebymarkedly increased.

The invention is defined, in the appended claims and is ,to-beconsidered comprehensive of .all forms of structure comin wi hi l e s p -1 cla 1. A,spacer and expander for supporting, spacing and outwardly pressing generally fiat, parted, thin rails in a ,piston ring cornprising, a generally circular, corrugated ,-le ngth ofjflat,met al ribbon stock having abutting ends and parallel longitudinal edges, the corrugations comprising an outercircnlar series of crowns having a straight outer portiomand aninnercircular series of crowns, the crowns .of ithe wtiivoeseries. altea'nating with .respect to ,each other and said two series of crowns being concentric, said alternate inner and outer crowns having integral generally diverging connecting legs extending from one to the other, each of said legs having a central portion and oppositely curved end portions integral "with adjacent crowns, said legs each being longitudinally slotted between opposite edges,i s'aidfslots'lextending into .the crowns associated herewitbasashls havin two eas P rt o generally para elin a pthe t e out edg .of v ai e Por i and edges of the outer 'crown portions being located between two spaced parallel planes, and each inner crown at each end therof-having-an integral lip extending there from a predetermineddistance beyond said planes.

2. A spacer and expander for supporting, spacing and outwardly pressing generally flat, parted, thin rails in a piston ring comprising, a generally circular, corrugated length of flat metal ribbon stock having abutting ends and-parallel longitudinal edges, the corrugations com- .prising .an outer circular: series of crowns and inner circulai' series ,of crowns, the crowns of the two series alternating wit-hrrespect to .each other and said two series of crow'nsubeingv concentric, said alternate inner and outer crowns uhav'ing integral generally diverging connecting .legse'xtendingfrorh .one to the-other, each of said-legs having-.a .centralportion and oppositely-curved ,end portions-integrahwit-h adjacent. crowns, said legs each being .andeach ,inner crown .ateach. end thereof having an integralulip extending therefrom a predetermined distance beyondusaidiplanes, said lip: being inclined away from the series of crowns.

References Cited in the file of this patent UN TED STA ES PATEN 2,383,825 Smith Aug. 28, 1945 2,635,022 .Shirk Apr. 14, 1953 2,695,825 Estey Nov. 30, 1954 

